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  • leafcutter ant problem

    Created by leaf cutter ant on

    I need advice on how to control leaf cutter ants. Last year they repeatedly defoliated apple and pear trees, black berries, rosemary and other perennials and trees that have been in the ground a little over a year. Most of these put on new growth only to be defoliated again. I have wood chip mulch around the plants and would like to stay as organic as possible, especially on the edibles. These little composters work quickly and can be done in a day once they get started. I plan to try the TangleFoot Pest Barrier on the trees, but that wouldn’t be too practical on the perennials. I’d like to be ready for them when things begin sprouting again. Any advice would be appreciated.

  • Author
  • #13759

    Mole Farmer

    Do you know where their nest is? If so, try using diatomaceous earth. It's not really a poison, but kills ants that crawl through it by scratching up their hard outside layer. (Do ants have an exoskeleton?) They eventually die of dehydration.

    Boric acid may work too! I know that it works on other ants.

    You could also try drenching the mound with a botanical insecticide, like pyrethrin. While it most likely won't get the entire mound, it certainly should reduce their numbers.



    I am having some success with using beneficial nematodes. I’ve been spraying the area where they are going into the ground and putting as much down the tunnels as possible. I try to apply after rains as the ant feeder sites are often on non irrigated areas. The nematodes live longer and multiply faster in moist soil.

    I think the main nesting site is on someone else’s property as I have not found it yet.

    I am also spraying the foliage of the plants they are harvesting with Biorganic spray. It is a mix of essential oils. They change their feeding site after an application of this.

    I have not had much success with boric acid or DE in treating them. They often forage up to 2500 feet or more from the main colony and can nest 10 to 12 feet underground. We have very sandy soil so they can go quite deep and they have many underground tunnels to the main nest site. I have tried many, many things over the last 25 years.

    They are fascinating creatures, but what a pain! Good luck!


    Eric Vinje

    Hello –

    Leaf cutter ants can wreak havoc in a relatively short amount of time and are known for causing serious agricultural losses in parts of the Southern United States. To combat this curious insect we recommend the following products.

    • Tanglefoot Insect Barrier will prevent them from reaching the leaves that they seek. Best of all, it contains NO pesticides.
    • Diatomaceous earth, boric acid and Orange Guard® will help reduce the mound. All are safer than conventional poisons.
    • Bonide® Pyrethrin Garden Insect Spray is a powerful botanical insecticide that provides a quick knock-down of most problem insects.

    Hope this helps!

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